Projection video display (PVD) systems based on digital mirror devices (DMDs) have become quite popular due, in part, to their accurate color rendition, resolution, display size and cost. For DMD-based front-projection PVD systems, the projection mechanism and a viewer are on the same side of the screen. To avoid key-stoning effects, DMD-based front-projection PVD systems often project light beams from the projection mechanism to the screen using a low angle of incidence (AOI) with respect to the normal of the incidence plane of the screen.
The use of a low AOI can be problematic, however. For instance, the viewer cannot interact closely with the projected image. If the viewer approaches the image, the viewer can block the projected image and cast a shadow on the screen. To facilitate closer viewer interaction, projection mechanism can be brought closer to the screen, e.g., closer and above, or, closer and below, the screen. However, a shorter throw distance between the projection mechanism and screen is associated with a higher AOI. Projecting light with a high AOI can, in turn, result in decreased brightness of the image projected on the screen. Moreover, the brightness of the projected image can be non-uniform across the screen.
What is needed in the art is a screen, and a front-projection PVD system using such a screen, that can minimize such specular reflection and enhance screen brightness.